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The result is a step towards "lightwave electronics" which could eventually lead to a breakthrough in quantum computing, says co-author Mackillo Kira from the University of Michigan.

Electrons moving through a semiconductor in a computer occasionally run into other electrons, releasing energy in the form of heat.

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Lightwave electronics, however, means electrons could be guided by ultrafast laser pulses so they are less likely to bump into other electrons.

"In the past few years, we and other groups have found that the oscillating electric field of ultrashort laser pulses can actually move electrons back and forth in solids," said Rupert Huber, from the University of Regensburg, who led the experiment.

"Everybody was immediately excited because one may be able to exploit this principle to build future computers that work at unprecedented clock rates - 10 to a hundred thousand times faster than state-of-the-art electronics."

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The new work has made groups of electrons move inside a semiconductor crystal using terahertz radiation, part of the electromagnetic spectrum between microwaves and infrared light.

The researchers shone laser pulses into a semiconductor. The pulses were very short, at less than 100 femtoseconds, or 100 quadrillionths of a second.

Each time a pulse was emitted, the electrons moved to a higher energy level and were free to move. By changing the orientation of the laser with respect to the crystal, the researchers could control the direction the electrons moved.

"The different energy landscapes can be viewed as a flat and straight street for electrons in one crystal direction, but for others, it may look more like an inclined plane to the side," said Fabian Langer, coauthor on the paper, also from Regensburg.

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"This means that the electrons may no longer move in the direction of the laser field but perform their own motion dictated by the microscopic environment."

When the electrons came down from the higher energy level, they emitted light in much shorter pulses than the radiation going in. These bursts of light were just a few femtoseconds long, and revealed where the electrons had moved.

"There are fast oscillations like fingers within a pulse. We can move the position of the fingers really easily by turning the crystal," said Kira

Femtosecond can potentially be used for quantum computations using electrons in excited states as qubits – quantum mechanical bits.

In classical computing, a bit is a single piece of information that can exist in two states – 1 or 0. Quantum computing uses quantum bits, or 'qubits' instead. Unlike a usual bit, they can store much more information than just 1 or 0, because they can exist in any superposition of these values.

"For example, here we managed to launch one electron simultaneously via two excitation pathways, which is not classically possible. That is the quantum world. In the quantum world, weird things happen," Kira said.

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"This genuine quantum effect could be seen in the femtosecond pulses as new, controllable, oscillation frequencies and directions.

"This is of course fundamental physics. With the same ideas you might optimise chemical reactions. You might get new ways of storing information or transmitting information securely through quantum cryptography."